[wasm] Int64Lowering of Word64Ctz.

src/compiler/int64-lowering.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/int64-lowering.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/diamond.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 524 matching lines @@
           MachineRepresentation::kWord32,
           graph()->NewNode(machine()->Int32Add(),
                            graph()->NewNode(machine()->Word32Clz(),
                                             GetReplacementLow(input)),
                            graph()->NewNode(common()->Int32Constant(32))),
           graph()->NewNode(machine()->Word32Clz(), GetReplacementHigh(input)));
       ReplaceNode(node, low_node, graph()->NewNode(common()->Int32Constant(0)));
       break;
     }
     // kExprI64Ctz:
+    case IrOpcode::kWord64Ctz: {
+      DCHECK(node->InputCount() == 1);
+      DCHECK(machine()->Word32Ctz().IsSupported());
+      Node* input = node->InputAt(0);
+      Diamond d(
+          graph(), common(),
+          graph()->NewNode(machine()->Word32Equal(), GetReplacementLow(input),
+                           graph()->NewNode(common()->Int32Constant(0))));
+      Node* low_node =
+          d.Phi(MachineRepresentation::kWord32,
+                graph()->NewNode(machine()->Int32Add(),
+                                 graph()->NewNode(machine()->Word32Ctz().op(),
+                                                  GetReplacementHigh(input)),
+                                 graph()->NewNode(common()->Int32Constant(32))),
+                graph()->NewNode(machine()->Word32Ctz().op(),
+                                 GetReplacementLow(input)));
+      ReplaceNode(node, low_node, graph()->NewNode(common()->Int32Constant(0)));
+      break;
+    }
+    // kExprI64Popcnt:
     case IrOpcode::kWord64Popcnt: {
       DCHECK(node->InputCount() == 1);
       Node* input = node->InputAt(0);
       // We assume that a Word64Popcnt node only has been created if
       // Word32Popcnt is actually supported.
       DCHECK(machine()->Word32Popcnt().IsSupported());
       ReplaceNode(node, graph()->NewNode(
                             machine()->Int32Add(),
                             graph()->NewNode(machine()->Word32Popcnt().op(),
                                              GetReplacementLow(input)),
                             graph()->NewNode(machine()->Word32Popcnt().op(),
                                              GetReplacementHigh(input))),
                   graph()->NewNode(common()->Int32Constant(0)));
       break;
     }
-    // kExprI64Popcnt:
 
     default: { DefaultLowering(node); }
   }
 }
 
 void Int64Lowering::LowerComparison(Node* node, const Operator* high_word_op,
                                     const Operator* low_word_op) {
   DCHECK(node->InputCount() == 2);
   Node* left = node->InputAt(0);
   Node* right = node->InputAt(1);
@@ skipping 49 matching lines @@
 }
 
 Node* Int64Lowering::GetReplacementHigh(Node* node) {
   Node* result = replacements_[node->id()].high;
   DCHECK(result);
   return result;
 }
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8